Positive plate for storage batteries and process for the manufacture thereof.



' 1 .11. SALOM..

' POSITIVE PLATE POE STORAGE BATTERIES AND PROCESS FOR THE MANUFACTURETHEREOF.

' 'APFLIOATIOR FILED JULY 27, 1909.

991,897; PatentdMay-9,1911..-

' FIGI;

INVENTOBI- Bedw (ii-Jam,

electrolytically duct technically termed, the forming into ac- .To, allwhom it may concern:

, w th, being Serial course be understood-that my invention is UNITEDSTATES PATENT OFFICE.

PEDRO e. SALOM, or rmrannnmira, PENNSYLVANIA, ASSIGNOR, BY

nears Be it known that I, PEDRO G. Samar, of Philadelphia, in the countyof Philadelphia and State of'Pennsylvania, have invented certain new anduseful improvements in Positive Plates for Storage Batteries andProcesses for the l\Ianufacturev Thereof, whereof the following is aspecification, reference being had to the accompanying drawings! In saiddrawings, I have shown a preferred form of conducting support adaptedfor use in connection with my invention, which support constitutes thesubject of an application filed No. 509,857 but it will of not in anyway limited to the use thereof.

"As at present oonnnercially conducted,

and apart from theoretical or practically abandoned methods, themanufacture of the positive. plates of lead storage batteries isessentially, conducted by mechanically applying red lead, inthe form ofa paste or cement, to a supporting conductor, and then converting thered lead. into lea'dperoxid, in site, that is to say, although vthe intial n'iaterial from which the active I material of the plate 18ultimately to be.

e is applied niechanicallyto the coning;support, the conversion .or, asit is 5 tiveinaterial is effected after such applica- Mon.

The object of the present invention is to permit the production of theultimate active Inaterialin bulk, and its application to the i beproperly termed support in what may footed without any intervention ofelectro- 'lytic actio'n at that stage ofthe process.

a Side elevation V of the broken vertical section thereof on an, en-

4 Beferring to the drawings, I will now de-- scribe the "conductingsupport, or grid, which I findfpeculiarlywell ad. gted to use inconnectionwith my improve process.

said -drawings, Figure 1, represents grid; Fig. II, is a [S ale Ijt'akenon, the line II, II, of

I, is .a'brokenhorizontal sec- F g-v consists of'an open rectangular andsimilar main bars contemporaneously here .I proceed Such applicationv iscf- Q l lan'e'ulaar'ged scale, on the line,

MESNE ASSIGN- Patented May 9, 1911. Serial No. 509,856.

frame 1, provided with main bars 2, ex tending atintervals from top tobottom, 3, extending at inter- Yals horizontally from side to side. withintermediate secondary bars 4, sub-dividing horizontally the rectangularconumri'mcnts formed by the main bars. The whole s 'l'ucture ispreferably cast integrally from antinionial lead. 1 I have found that agrid of this forn'ris peculiarly adapted for the ap plication of theactive material by hydraulie pressure, which is effected at onc,stagc ofmy process:

Inthe practice of my present invention, as follows :I first obtain. amass of lead peroxid in bulk, preferably by the following process: Anelectrolytic cell of leadis packed-with a layer of spongy lead in closeelectricaland mechanical contact with the bottom of the interiorportion. An electrolyte, preferably of sulfuric acid and water, isemployed and lead cathodes aresuspendcd in the electrolyte a shortdistance above the mass. When an electric current passes, the leadvessel and the spongy lead maintained therein constitute the ani oforgygen takes spongy lead into lead peroxid. The peroxid obtained as theresult of this process, or otherwise produced, is properly dried andground, so as to be in the form of a mass of definite particles Theseparticles are then mixed with a binding material, the latter being inrelatively smallproportion's and haviiigc'such physical characteristicsas to permit the composite mass to undergo a high degree of compression.Furthermore, the chemical character of the binder should be such thatit, or its derivatives under treatment, 'may be re tained withintheplabe, without detriment structural strength or electricalcharacteristics of the latter, as distinguished from a binder of foreignmaterial, must either be re1noved,-or if retained, disadvantageouslymodifies-the plate. I prefer to use ground litharge as the bindingterial, preferably in a pro ortion between tenand twenty :per cent. 0the total mass.

When litharge is employed'as the binder, I-

disseminate it thoroughly by admixture with intervening voids;

with th'elper'oxid particles, and moisten the whole mass with sulfuricacid and water, the quantity of acid in the solutionpreferably beingfrom about ten to twenty per 5 cent.,by weight thereof. The moisteningingredient, such as dilute sulfuric acid, is employed in very limitedquantities, so-as not to form a pasty, Q1 semi-liquid body, but

merely a damppned mass of definite par ti'cles having a out the temperof molding sand, the litharge being preferably only partly converted bythe action of the acid, and its particles being'disseminated with asmuch uniformity as possible through the peroxid particles. The mass of'material thus obtained has thecharacteristic of lend.- ing itself to theapplication of heavy hydraulic pressure, without the. disruptingtendency which would be manifested if the 2 quantity of liquid wererelatively large, and

at the same time afi'ording the necessary cohesion to the mass for-theapplication thereof to the grid. When litha-rg'e is thus used, I believethat the physical condition above referred to corresponds with thepres-' ence of about ten per cent. (in weight) of the liquid ingredientto the total, massof peroxid and binder. The mass of dampened particlesis .then applied to the grid and compressed "thereon by means of a heavyhydraulic pressure, such cbmpressing action being rendered possible byreason 0tthe V physical condition above mentioned, as dis tinguishedfrom that of a substantially coalescent semi-liquid or pasty body.W-Yien' the plate is -,removed from the ress,ftlie active material willbe found tobe in a coherent condition, but in order 'to insure,

its'permanency, I prefer to treat it after 40 compression asfollo\vs:-The plate is 4 dipped in water and afterward treated with amixture of sulfuric acid and water, the

quantity'of the acid i'n-the solution preferably not exceeding ten percent.- thereofij This treatment substantially converts the remaininglitharge intosulfate, and thoroughly binds the mass of peroxid together,without,.however, depriving it of the required porosity.

I have found that the plates embodying. my invention are'not only highlyhomoge- 'neous and electrically efiicient elements, but that they carrya relatively greater quantity of active material than can be applied toa given supportby the processes actually use.

When the. plate is formed by the electr c-- lytic conversion of red leadinto perox'id, in

situ, the reaction is attended by expansion of the applied material, andit has a tendto loosen itself and become detached .ency y from thesupport' By 'my invention the peroxid is initially f formed in thecondition 1n which it isto be used, and since it 55 does not undergo anyexpansion in the act plioation of hydraulic pressure to the plates;

as a whole, by.reason of the practical.-noii-'- initially formed .1 thegrid (as in the Brush-Faure plate), this for storage battery;

ducting support having a homogeneous; f mass. coherently compressedthereon, said of originally "producing the plate," it has no tendency tobecome detached therefrom, at that stage of'its existence, Furthermore,

the process which forms part of my inventlon possesses valuable featuresof econ'-. only, since the electrolytic conversion of lead intospo'ngylead, and the conversion of the latter into lead peroxid, in bulk costmuch less than the equivalent amount .of

red lead (which is the ordinary source of active material) at. therespective prices prevailing for these ingredients.-

In the foregoing specification I have de-- scribed litharge as thepreferable. binding material, and. haveset forth that feature of so therocesswhich is addressed to its proper app ication and treatment. I donot, however, limit myself to theuse of-lithargeas' a binder, thedesideratum of the'binder-being thatit'shall not, when initiallyappliedy'sfi produce such a semi-liquid or pasty con dition, asv tointerfere with the proper ape:

compressibility-of any material whicha'is so substantially ,in a liquidor homogeneous :1,

pasty condition. It .isalso important that the chemical character of thebinder-shall. be such that it or its derivatives under treatinent mayremainin the plate without im-' pairing the latter. Havingthusdescr-ibed my invention, I" wish to point out that the essentialdifference between the plate thus. manufactured and those-of tl1e ipr1orart',res ides in the fact that in my inventionthe active material isexternallyto the plate itself, as distinguished from. being'electrolytically formed by the oxidation of the'support itself (as-inthe original Plant plate),uand as distinguished I from 'bein formed insitu, by the electrolytic oxidation of 'a materialmechanically appliedto mass" consisting substantially of externally formed act1ve m'aterialobtained in-the condition of definite particles andhaving solidparticles of binding material intimately}, disseminated. throughout themass. i

2. An initially formed positive plate for a storage battery,

consisting of a, con- 1.

*eerga w v [ducting support l avingj a mass of active mingled ileadperoXid and litharge until said material coherentl compressed thereon,said mass has about the temper of molding sand,

mass consisting su bstantiallyof externally, and compressing the saidmass upon a conformed perpxid'of lead obtained in the ductin support,substantially as set forth. g condition of definite particles,andhavi'ng -5. Te hereinbefore described process for j particles ofsulfate 0 lead intimatel dis-j the manufacture of positive plates for aseminated throughout the same, where ythestorage battery which consistsin initially particles of peroxid are homogeneously forming amassof-peroxid of lead obound together. tained in the condition of definiteparticles, 5

3. The hereinbefore described process for adding litharge theretoinabout the proporthe manufacture of initially formed positions specified,noistening the mass of tive platesfora storage battery, which oonmingledlead peroxid and litharge with disists in disseminating particles of asolid lute sulfuric acid until said mass has about i forming a mass ofperoxid of lead obbinding material throughout a pre onderatthe temper ofmolding sand, compressing 40 ing {mass of peroxid of lead, said peroxidthe mass upon a conducting support; and being in the condition ofdefinite particles, treating the plate with dilute sulfuric acid andicompressing, the resultant mass 'coto effect the conversion of anypreviously herentlyupon a conducting support, subunconverted lithargeinto sulfate, substans'tantially as set forth. ti lly as set forth. v 4.The hereinbefore described process for lIn testimony whereof, I' havehereunto the manufacture of positive plates for a signed my name, atPhiladelphia, Pennsylstorage batterywhich consists in initially Vania,this twenty-sixth da of July, 1909.

8 G.- SALOM. tained in the condition of definite particles, VVitnessesradding litharge thereto in about the propor- JAMES H. BELL,

"tions'specified, mo1stening the mass .of L. FULLERT N.

